The production of gas from `tight sand` deep wells has always created a challenge to gas well operators. In many areas of the United States, pockets of combined gas, oil and brine deposits are entrapped within porous sandone formations. In the Northern Pennsylvania, Ohio, and Northwestern New York State gas exploration areas, hundreds of gas wells have been drilled into such formations. In order to achieve practical gas production from such wells, it has been the general practice to set up a two tube or pipe system to enable effective removal of well fluids, i.e. oil and brine, that interfere with gas production.
The more sophisticated and state of the art systems use an electronic control to allow preset cycling of production and fluid removal periods, as described in U.S. Pat. Nos. 4,150,721, and 5,146,991, however some older patents, i.e. U.S. Pat. Nos. 3,053,188, 3,203,351, 3,266,574, 3,396,793, and 3,863,714, have been investigated, and have described some unique instrumentation, utilizing well pressure entirely to control well cycling and operating functions. The technology covered in these patents and many published articles concerning the art, all have contributed to define the gas production methods to the present level, and may be used in conjunction with the subject invention.
As a rule, operator experience and frequent attention to an individual well assures satisfactory operation, and adequate production from the `tight sands` gas wells for significant periods of time. Many gas wells have produced profitably for periods exceeding 10 or 15 years. When the wells are depleted past their prime, however, the cost of production, i.e. the time, effort, and related expenses to keep the wells producing, may begin to exceed their income. Usually, only 30 to 50% of the predicted gas formation reserves may have been extracted at this point, wasting the remainder of the potential capacity. The customary decision then is to `plug`, or cement the well, as required by law. This procedure involves the complete cementing of the well hole, at substantial cost to the gas well operator.
The problem with conventional gas production methods from `tight sands` wells has been the inability to predictably adjust to the changes in the production capability of the well. The decisions to produce, and fluid removal on a predicted schedule, have been left to the experience and skill of the well tender. Quite often, the well may be overproduced, it becomes `waterlogged`, and the residual natural gas pressure is incapable of `lifting` the accumulated fluids from the well. Extended periods of `shut in` are then necessary to recover the pressure, and to force the excess fluids back into the formations; as a result, considerable production time is lost. Secondly, this shut in period is followed by exhausting, or `blowing` the well to the atmosphere, in order to remove the excess fluids and `clean up` the well. This loss of time and natural gas results in considerable loss of revenue. A more efficient production method is called for to fully utilize these untapped gas reserves. The inventor has developed and successfully proven such a system to overcome the above mentioned production deficiencies, and allow nearly complete exhaustion of the predicted reserves. It is identified as `Tight Sands Gas Well Production Enhancement System`, and described herein.